Elkhart Brass Stinger RF8297 - Manual (Page 29)

26
VIII. M
ONITOR
& S
TREAM
S
HAPER
H
YDRAULIC
D
ATA
Interpreting Flow Data
The following graphs offer the pressure losses for the monitor (and other devices) in
terms of Total Static Pressure Drop. This Total Static Pressure Drop can be found by
measuring the difference between the static inlet pressure and the static outlet pressure.
The static pressure at either of these points can be found using a simple pressure gauge.
An illustration of this method can be seen below.
In mathematical terms, the Total Static Pressure Drop is the change in Velocity Pressure
plus Friction Loss. The change in Velocity Pressure results from the change in velocity
of water caused by the change in the cross section of a waterway. Friction Loss results
from the drag and sidewall interference of the water through a device. A simple equation
can be seen below.
In the firefighting industry, the terms Total Static Pressure Drop and Friction Loss tend to
be used interchangeably. However, these are significantly different measurements. This
misconception could ultimately lead to lower than anticipated performance from
equipment. When designing a system and determining performance, Total Static
Pressure Drop is the value that should always be used. The Friction Loss curve is also
supplied in order to make a comparison with competitor products that may only supply
Friction Loss curves. If there are any further questions regarding this matter, please
contact Elkhart Brass.
ΔP
S
= H
F
+ ΔP
V
ΔP
S
= Total Static Pressure Drop
H
F
= Friction Loss
ΔP
V
= Velocity Pressure Loss